It is indeed an extinct animal. I guess you should have confused it with the modern cape mountain zebra which is small. I forgot to add the word 'giant', it's the giant cape zebra. You might have had a doubt about it's large size, if you didn't then that will be surprising because modern zebras are not that big. Search - equus capensis. These are most likely the largest zebras to have existed and among the largest equids.

This is an amazing drawing. My only criticism is that it is missing the following dinosaurs: Afrovenator, Aegyptosaurus, Bahariasaurus, Deltadromeus (assuming Deltadromeus and Bahariasaurus are different animals; which is my theory at least), and Rugops